Touchfire is a flexible, physical keyboard for the iPad. Its inventors recently redesigned it to fit the iPad mini--and it was more complicated than they expected.

Touchfire's designers also created their own customized smart cover for the iPad mini, because Apple's version "turns the iPad mini into a little trampoline when you type quickly."

The Touchfire's ergonomic design guides your fingertips to just the right point to register a comfortable keystroke on the iPad mini's virtual keyboard.

As with the full-sized Touchfire, the redesigned keyboard folds up within the iPad mini's smart cover so that you never have to be without it.

The iPad mini's virtual keys were too small to be usable as physical buttons, so the Touchfire's designers stretched and squeezed certain keys in order to fit them comfortably over the touch screen.

The Touchfire is made out of flexible material so you don't have to worry about cracking or breaking it.

The new Touchfire folds into the smart cover without adding any additional thickness to the device.

Stretching and squeezing the Touchfire's keys was a clever solution to the ergonomic problem, but implementing it in a way that offered just the right amount of subtle springiness that touch-typers expect "was not a straightforward process," say the designers.

The new Touchfire's Kickstarter campaign surpassed its $10,000 goal within 24 hours of launching, so people must be excited about typing on a tiny iPad mini.

The original Touchfire keyboard was big enough to simply sit over the iPad's virtual keyboard and map to its keys exactly.

Kickstarting: A Flexible Keyboard For The iPad Mini

This is the story of how Touchfire downsized its original iPad keyboard to fit Apple's smaller tablet. Spoiler alert: It wasn't really about shrinking it.

A little less than two years ago, Steve Isaac and Brad Melmon invented a physical keyboard for the iPad called Touchfire. It raised over $200,000 on Kickstarter; we loved its ergonomic design and attention to detail. Now Isaac and Melmon are back on Kickstarter with a Touchfire that's downsized to fit the iPad Mini. But fitting physical keys to the Mini's diminutive screen wasn't as simple as shrink-raying the original Touchfire—it took Isaac and Melmon eight months of design effort to pull off.

Why was redesigning the smaller Touchfire so tough? Simply shrinking the original Touchfire resulted in keys whose "pitch"—or the space between keys—was "drastically reduced" to the point of being unusable. Luckily, "it turns out that all keys are not equal when it comes to key top area needed for them to work effectively," Isaac tells Co.Design. "We discovered that the central keys, like the "G" and "H" on all rows could be "squeezed" in side to side, while keys closer to the outsides could be stretched out. That allowed us to spread the tactile centers of the keys, essentially increasing the perceived pitch from side to side."

This stretching and squeezing of physical keys was a clever solution to the ergonomic problem, but implementing it in a way that offered just the right amount of subtle springiness that touch-typers expect "was not a straightforward process," Isaac says. "It required quite a bit of observation: How do people type? How do they locate their fingers and realign?" The designers also found the iPad Mini's cover less than satisfactory as a physical support for the new Touchfire. "[It] turns the iPad mini into a little trampoline when you type quickly," Isaac says. So he and Melmon went back to the drawing board to create their own cover, optimized to offer four different typing angles.

I was skeptical about whether a physical keyboard for the iPad Mini was a solution in search of a problem. Did Mini users really want to treat their tiny tablets like laptop replacements? Given that the Touchfire's Kickstarter campaign surpassed its $10,000 goal within 24 hours of launching, I stand corrected. "[Our users] weren't thinking about it as a laptop replacement," Isaac explains. "They were well beyond that—thinking about how it would replace the [full-sized] iPad that had already replaced their laptop."